I am a newbie and would like to know the differences in implementing a two way with Titanium dome tweeter vs two way with Ribbon element tweeter. Thats a question in general taking typical transducers.
In particular, I am considering the Dayton ribbon

Neither one.
If you want to use Titanium dome tweeter than I would recommend Seas 27TBFC/G H1212 or 27TBFC/GTV H1213 or 27TBC/G H1147 or LPG 26T.
As for the differences; the main one would be with dome tweeter the listening position (off axis) is not as critical as it would be with Ribbon but the crossover also affects that. Also the dome tweeter generally can be crossed over at lower frequency than most Ribbons and have higher rating power generally. You can get a real great sounding metal dome for under $40 but with ribbons a good sounding one will cost at least 3-4 times more.

SY

22nd January 2004 12:37 PM

Titanium

Don't overlook Audax's DT101, though I'm not sure what the shielding is like. It sounds great, very detailed and sweet.

VictorG

22nd January 2004 09:52 PM

On the ribbon-

Its very interesting because I picked up an almost identical unit from madisound but made by a company called silver flute. I mean im 99% sure they are the same things by parts pics...

I was building up some relativly inexpensive l/r speakers and bought one of each, this model and the other ribbon that silver flute makes if you look on madisounds webpage.

The one you have pictured definatly has more radiating area and thus can really hit its lower F values given. I ended up going for the smaller model cause I wanted to keep the box size down, but the one you have pictured sounds great.

I like the sound, but just bear in mind that like anything planar the sound is more planar than your typical cone or "titaniuM dome" in this case. Also i dont listen to rock persay, these days Im more into peter gabriel, sting, phil and the like and am looking to hear strain in the voice.

If you are after rock and want it loud, i wouldnt waste my time in the planars. The dome will just handle more power better. If you want details and accuracy go planar.

Regarding high power for rock I would say the target use is for Rock but with medium power (Its a 14 x 10 feet room).

What about the performance in HT 5.1 application. Shielding is problem i know with both. And what about other subjective issues, like transient response, soundstag etc about which the technical params dont give a clue . How much will be the difference in sound if a decent crossover is designed. Is the price difference well worth going for the ribbons. I am talking of 5 nos of Ribbons vs 5 of titaniums. Both also have different recommended crossover frequencies. I have no idea about the difference in sound due to these different crossover frequencies.

If I go for 'a' choice I will be restricted to only TM config due to the price of these woofers.

If I go for 'b' or 'c' choice, I would go for MTM config for fronts and centre and TM for surrounds.

Stereo subs will be added, either vented as seperates or TL in front left and right speakers. I am still studying the deifferences in both alignments and you will hear more on this later.

Speaking of MTM vs TM. I believe that MTM cannot be crossed high enough due to centre to centre differences. So crossover frequency will play a role here. Am I right? What is the rule of thumb for knowing whether my MTM satisfies the condition.
Are there any other rule of thumbs for a combination of this kind.

I hope this thread provides me enough info to have a very good setup.

Thanks in advance.
Goldy

VictorG

25th January 2004 07:04 AM

I guess the central question is this:

Are you going to be using the system snuggled up next to a girl or are you gonna have alot of dudes over to watch the game?

The problem unfortunatly is this: Planars have a shorter dispersion field no matter what the manufactur says. Just look at that planer you were thinking of, that 1/2 inch of waveguide is not gonna disperse sound all that great. When you get a 5.1 setup going, you are going to have to focus it on one seat, maybe a couch. The sweetspot will exist in a small area.

If you do the titanium tweeters, you will notice being in and out of the sweetspot less. Owning two of the ribbons you pictured though, i can definatly say they are sweet spot oriented, at least relativly so in comparison with say a dome.

As for transient ~= soundstage, the planars will kick the domes *** in my humble opinion. But of course that is just my opinion and someone is likely to say otherwise. But then i own the ultimate planar spekars, 100Hz-25K Electrostats.... hehehe.

So we come back to the central question, you using this for solo analytical listening, or do you want about the same quality of sound in most areas of the room. Planars for the former, domes for the latter.

So you want both? Sadly you have hit upon the central problem in audio: tradeoffs. if z is over all sound, x is dispersion and y is transient response, unfortunatly, z=xy. At least thats my expierience in audio. Of course thier is one factor which lets you change that equation.

z=$xy.

I am only 20, and can honestly say I've sunk 2k into audio. Have fun! Just dont expect TOO much out of a budget system (transient + dispersion)

goldyrathore

27th January 2004 04:52 AM

Some more questions

Hi,

In the short term I'll go for the dome and leave the planars for my next project.

Here comes another volley of questions.

1a> Which of the woofers I mentioned will mate well for the Titaniums.
1b> Should I go for vented or sealed. In case of vented design, do two ports have an advantage over single port?
1c> How low should the woofers go?. The woofers I mentioned have quite different Fs. Can we have a discussion on these woofers.

2> I had earlier decided LM3875 amps but they are not available locally. LM3876 is avialable instead. Is there any subjective quality differences in sound between these ? Can you folks recommend me a better discrete design providing about 40-50W of clean power into 4 Ohms .

3> For the purpose of being different, I plan to mount the tweeters outside the woofer cabinet as in most B&W speakers. This will yield a lower diffraction effect.
a> Can I make the speakers trianular instead of rectangular. I guess it will yield a more rigid and non reflecting box. How much of this will be translated into good sound? The only drawback is that the subs will have to be separates. Once I have answers to all these questions I have a lot to ask on various subs.

4> Crossover: I intend to experiment with Linkwitz-Riley 12db/octave as well as 24db/octave with various crossover points. But this crossover does not take into account the phase response of drivers. I mean I know at crossover point they are phase linear. But add the drivers own phase responses and I think the subjectivity comes in. No wonder one of the commercial 2 Way floorstander had good reviews with an approach where they had Linkwitz Riley crossover with custom compensation for each driver. Now if this is so good, I am sure some one would have already done it before.
4a> Is it possible in the first place?
4b?Can someone provide give me links to designs on similar idea?

Thanks Goldy

VictorG

27th January 2004 05:27 AM

Ah the devil is in the details.....

1a.) Problem here is this, that Dayton goes lower in the Hz range, but it can only take 45W peak, 30RMS.... and you said you were looking to get an amp.... oh and the efficientcy on this guy sucks... (83db)

Um you could go with that Vifa JBL speaker, the efficiency matches up with that dome tweater (both 89) which makes things easier. On this note alone I'll say of the three, go with this driver....

The only disadvantage to this driver is its relativly high Fs. (58Hz)
We'll fet to the implications of this in a miniute.

1b/c.) Sealed or ported.... you want to go sealed for your first project. Why you ask? Beacuse you can screw it up and so long as its not too far off (< 25% off) and you have a good seal (caulking) its gonna sound good. The advantage to ported is only that you could hit closer to that Fs, just a guess 75Hz maybe. Know that with sealed, again a guess, you are only going to be able to hit 95-105Hz. Again, audio is about tradeoffs but you should choose losing 20 Hz instead of having a terible first DIY project. Lots of variables in ported to mess up.

2.) I actually can give much adivice here... I am just compleating my first amps myself and do not consider myself expierienced enough to advise here. I'll just say you might want to consider getting a commercial amp to start out with (hafler, bryceton ect.) so you have a working amp to pair with you speakers when you get done. You'll find when you build an amp the constant tug to modify, so having a standin amp wont be a bad thing even if you buildup an amp of your own. And constuction amps isnt cheap either, I havent constucted a purist chip amp, but toss in some nice chips, some audio grade caps, binding posts, wiring, rocker, chassis and all the otehr little things and you will soon be at ~125.

3.) Lets go over the facts real quick, you are going to invest about 60 bucks total in drivers and you are worried about "a lower diffraction effect"? KISS (keep it simple stupid), and i dont mean this as an insult but just as constructive advice. You remind me of a time when i bought 2 15 inch drivers and because I wanted to hit within 3Hz of its 22Hz Fs, I proceeded to build two refrigerator sized ported cabinets. Now only did I not get exactly my desired results (a complication with the ported design...), I had two MASSSIVE refrigerators. They only lasted two months before I used them for scrap. This is your first project, lets keep it simple. Put the tweeter in the box. Also B&W speakes have nice curved backing, check out the backing on that dome.....

3a) For the kind of speaker you are talking about using, if you use screws and 3/4 inch MDF your gonna be just fine as far as ridgidity is concerned. Make the shape what looks back. Angled cuts are hearder than they first seem for a new DIY cabinet builder, maybe my buddy will comment in on his resent "persision angled cuts"

4.) Sure, go for a LR crossover, but again, your spending $60 on drivers and you are worried about thier individual phase shift??? KISS. BTW- coils, caps, ect for those crossovers may soon add up to what you are spending on the drivers.

When you do constuct, use 3/4 MDF.

Open to discussion. I was you two years ago, I owe it to this community to help out a newbie or two.
Brian

CeramicMan

27th January 2004 11:35 AM

Yeah, keep it simple, but not too simple. There has to be a balance between what you want to get in the end, and how much effort you should put into your DIY endeavours. Most people just "buy" their loudspeakers, heheh... wierd! - No effort, no fun, and then they moan about the sound being bad!.... Since you're in the "choosing a speaker" stage :bawling: , here are a few things I learnt:

1) You'll end up spending a lot more time looking at different speaker options than you ever thought was possible.

2)Pay attention to waterfall plots, the frequency graphs are less than half the story. If a waterfall plot has what looks like sharp granite ridges, then those represent resonances that may not show up on frequency plots and might not even be audible. But they will make your loudspeakers harsh and tiring to listen to after a while, and will require a lot of that semi-bogus "speaker break-in". Audax publish the waterfall plots for their speakers for the world to see, as do some other manufacturers (who have enough balls ;) ).

3)You'll find that just about any speaker has unfavourable characteristics shown in its waterfall plot. Some of the resonances are unavoidable and are a characteristic of the cone material. Other resonances are caused by ringing of the speaker's metal "basket" (spokes 'n' all). Still others are caused by the impedance spikes often seen on tweeters at around 1.5kHz, and on woofers anywhere near 40Hz.

4)To help you later on with the crossover, you will want the impedance curve of the tweeter to stay as flat as possible. For this a damped "rear chamber" for the tweeter is required, which makes the tweeter sound a lot better anyway. Some of the best Vifa tweeters have rear chambers.

5)You'll need to choose woofers and tweeters that seem to have a ridiculous overlap from above 4kHz right down to less than 1kHz, or as much as you can realistically get. The tweeter doesn't have to have the same sensitivity or impedance as the woofer - little things like that can be fixed later with the crossover.

6)After a long time I learned that the cone material such as paper versus plastic, or metal versus fabric isn't all that important in the low to medium-high price ranges. It's only when it gets really pricey that some cone materials tend to stand out from the rest, and even then they all have their pros and cons.